The present invention relates to an improvement to read-write memories to enhance their useful life. More particularly, the present invention relates to improving a read-write memory, such as an EEPROM memory, that has only a limited number of write accesses, as well as a limited time for database organization.
The lifetime of a read-write memory depends heavily on the prevailing conditions of the application, especially on ambient temperature. Manufacturers of EEPROM memories typically guarantee a write frequency of 10,000 to 100,000 accesses. When these write cycles are exceeded, one has to be prepared for the fact that data may be corrupted in the memory. Therefore, the user has to ensure that the number of write accesses guaranteed by the manufacturer are not exceeded.
However, as laboratory tests have shown, the actual number of possible write accesses may be anywhere from 30 to 300 times more than the number of write cycles guaranteed by the manufacturer. However, any use beyond the guaranteed lifetime holds the danger of possible corruption of individual bits in the data memory.